Should We Play A♮ or A♯ in Beethoven’s “Hammerklavier” Sonata, Opus 106?

One hundred and eighty-five years after Beethoven’s death there is still a question as to whether to play an Ainline-graphic 02i] or A[inline-graphic 01i] in measures 224–26 of the first movement of Beethoven’s “Hammerklavier” Sonata, op. 106. Hans von Bülow’s reading of an A[inline-graphic 02i] has been repeated in numerous editions, although musicological evidence points to Beethoven’s intention of A[inline-graphic 01i]. The author presents six arguments in favor of the latter.